The ITV chairman, Michael Grade, yesterday promised a tough "one strike and you're out" approach to deception as part of an effort to tackle a widening crisis in viewer trust, warning guilty producers they would never work for the network again. Questioned by MPs on the media select committee, Mr Grade and the BBC deputy director general, Mark Byford, both accepted the sector was in crisis as a result of an avalanche of charges of viewers being deceived and defrauded.

Mr Byford, who led the trawl through 1m hours of footage that resulted in last week's revelations about programmes including Children in Need, revealed that the BBC would change its recruitment procedures, in addition to introducing a new training programme for its staff and suppliers. "As well as the training programme, we'll absolutely review the recruitment process ... we'll have to beef it up so that people who do join are left in no doubt what the BBC stands for."

Mr Grade, speaking ahead of the publication of a Deloitte audit expected to turn the spotlight back on ITV, said the current malaise, sparked by a rash of claims about premium phone lines and compounded by recent allegations that programmes had been rigged and competition winners faked, was "as serious as it gets".

Both ITV and the BBC have suspended commissions from RDF Media, the producer responsible for the faked footage of the Queen supposedly storming out of a photoshoot that was shown at a press launch. Mr Grade said any producer found to have deceived viewers would be shunned by ITV. "If [Big Brother producer] Endemol or any other production company is found to have set out to lie and deceive viewers, we can't do business with them. It's as simple as that. Zero tolerance means zero tolerance."

Asked afterwards whether the recent Ofcom judgment against Five, in which it was fined £300,000 over a programme made by Endemol that routinely faked winners, was enough to warrant ITV excluding the producer from its roster, Mr Grade said it was "too early to say". Last week the producer admitted that some sequences in another programme it made for Five, Killer Shark Live, had been pre-recorded.

Mr Byford refused to be drawn on the recent admission from RDF that it was a senior director who made the fateful edit of a trailer of a fly on the wall documentary about the Queen. He said he would await the outcome of an independent report commissioned from former BBC executive Will Wyatt, due to report in September.

Mr Byford admitted there was a delay between the BBC being informed by the Palace that the sequence gave a false impression and a statement being released. "There were reasons behind that delay but I want that to be part of Mr Wyatt's inquiry," he said.

The committee session had been convened in the wake of last week's revelations that six BBC programmes, including Children in Need and Comic Relief, had faked competition winners.

The deputy director general, who committee chairman John Whittingdale said had adopted a strategy of "self-flagellation", said he was "doubly shocked" that the problems came to light after an earlier trawl had failed to pick them up.

Mr Grade said the independent audit by Deloitte reviewing the use of premium phone lines by ITV programmes over the past two years was likely to report back "in a month or two". He also revealed that GMTV, accused of defrauding viewers of up to £10m over a period of years by allowing them to enter phone-in competitions they had no chance of winning, would deliver its own findings within days.

Meanwhile, media regulator Ofcom confirmed it would amend broadcasters' licences to make them directly responsible for premium line phone-ins and interactivity contained in their programmes.The change was one of the recommendations from last week's report into premium phone lines that suggested broadcasters were "in denial" about the scale of the problem.